TC Electronic Broadcast 6000 - Manual (Page 190)

Backdrop
186 System 6000 MKII Algorithms
MultiBand Model
Backdrop algorithm – MultiBand model page
The MultiBand model offers an enhanced set of
controls compared to the Basic model. The Mul-
tiBand model provides three independent noise
reduction engines split across three frequency
bands. Therefore you can apply as much or as
little noise reduction as is needed in each of the
three frequency bands. Of course, the cross-
over frequencies for the three bands are entirely
adjustable providing unprecedented flexibility in
how the noise reduction is applied.
The MultiBand model is a good choice for higher
levels of noise and when you need a high degree
of precision in where you apply the noise reduc-
tion. The MultiBand model provides the same
four primary controls (Aggression, Max Reduc-
tion, Basilar Dispersion, and Transient Recovery)
in each of the three frequency bands.
The Aggression, Max Reduction, Basilar Disper-
sion, Transient Recovery, and Link controls func-
tion exactly as in the Basic Model, except they
are split into three bands.
MultiType Model
Backdrop algorithm – MultiType model page
The MultiType model offers a unique and exciting
new approach to noise reduction. The MultiType
algorithm is based on the realization that most
noises are actually a sum of several different in-
dividual noise components. Moreover, the noise
components may not be equally annoying and
so it is sensible to apply more noise reduction to
the components which are most annoying.
For example, consider a recording that has been
corrupted by a combination of a hum due to
a ground loop, room rumble and tape hiss. In
such a situation one often finds that the tonal
components of the hum are more annoying than
the other two noise components. Therefore, it
would be very useful to apply the most noise
reduction specifically to the hum component.
Conversely, the tape hiss component might be
quite acceptable and so you might want to leave
it untouched while reducing the room rumble
component. Other noise reduction algorithms
operate on the composite noise signal and treat
each noise component equally. With BackDrop’s
MultiType algorithm you can selectively reduce
each of these three components while minimiz-
ing the processing applied to the signal you’re
cleaning up.
The way in which BackDrop decomposes the
noise into three components is best described
in the frequency domain as illustrated in above
figures. The first figure shows the spectrum of
the composite noise (i.e. Buzz, Room noise and
Hiss combined). The second figure shows how
BackDrop decomposes the noise into the three
components. The Buzz component consists of
the tonal parts of the noise. The Room compo-
nent consists of the broadband noise that does
not have a flat spectrum. The Room component